Solid and semi-solid cosmetic products, such as lipsticks and lip balms, are typically retained in stick or pomade form by an elevator cup that is extended and retracted along a track within a cylindrical sleeve of a dispenser body. The pomade can be loaded into the elevator cup either automatically or manually. With manual filling, stick-shaped pomades are typically pre-formed in a mold, chilled, and pressed into the elevator cup of the dispenser by hand. Automatic filling commonly involves molding and chilling the pomade and then ejecting it of the mold and into the elevator cup.
Historically, frictional forces between the pomade and the inside wall of the elevator cup were exploited to retain the pomade relative to the elevator cup and the dispenser in general. However, it is known that modern wear-resistant, silicone-based lipsticks commonly have reduced diameters as compared to conventional lipsticks. It has further been found that such cosmetic pomades tend to be slippery and to shrink over time. These factors have posed challenges to the secure axial and orbital retention of the pomade, particularly over time. Manufacturers commonly must conduct drop tests and other examination and testing seeking to ensure that retained pomades will avoid orbital and axial movement relative to the elevator cup during use.
Attempts have been made to improve the retention of such stick-like products in relation to elevator cups of retractable dispensers. For example, U.S. Patent Application Publication No. 2007/0217857 of Ho, U.S. Pat. No. 4,983,059 to Holloway, and U.S. Pat. No. 7,357,588 to Liard each disclose dispensers with a plurality of longitudinal ribs or fins that project inwardly from a peripheral wall of an elevator cup. In each instance, the ribs are designed to slice or project into the pomade once the pomade is disposed in the elevator cup thereby to assist in gripping it and preventing the pomade from shifting or becoming dislodged in relation to the elevator cup during use. With U.S. Pat. No. 5,609,430, Mazzola et al. sought to further combat the issues presented by slippery, shrinking cosmetic pomades by employing plural inwardly extending ribs that have a radial curvature for preventing axial and orbital displacement of the pomade. Even further, Spatz in U.S. Pat. No. 4,820,070 suggests employing ribs with dove-tail cross-sections.
Such rib configurations have represented useful contributions to the art and have assisted in better retaining cosmetic pomades during installation, transport, and use. However, even the combined prior art has left a plurality of deficiencies and issues with respect to the competing goals of seeking stable retention of a cosmetic pomade against axial and orbital movement while avoiding deleterious harm to the structural integrity of the retained cosmetic pomade. For instance, prior art structures with relatively abbreviated ribs or fins advantageously avoid excessive damage to the pomade structure, but they are limited in their resistance to orbital and axial displacement of the cosmetic. Conversely, prior art dispensers as taught, for instance, by Spatz and Mazzola et al. with irregularly shaped ribs might well achieve greater mechanical and frictional engagement between the ribs and the pomade, but the piercing the body of the pomade with irregularly shaped ribs produces the necessary result of localized, and at times generalized, deformation and damage to the pomade body. With that, the structural integrity of the pomade tends to be compromised thereby producing an elevated risk of structural failure during use or as a result of impacts on the pomade and the cosmetic dispenser in general.
It will thus be recognized that there remains a need for an improved elevator cup for stick-shaped products that provides stable support and retention of the pomade against orbital and axial displacement while avoiding excessive damage to the pomade and structural vulnerabilities deriving therefrom.